Improvement of MALDI detection sensitivity by promoting desolvation of matrix clusters

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K15242
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 47020:Pharmaceutical analytical chemistry and physicochemistry-related
• Research Institution: Niigata University of Pharmacy and Medical and Life Sciences
• Principal Investigator: SHIROTA Tatsuro 新潟薬科大学, 薬学部, 助教 (20714900)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: MALDI / 脱溶媒和 / マトリックスクラスター / 質量分析

Outline of Final Research Achievements

Matrix-assisted laser desorption/ionization (MALDI) is used as a soft ionization method such as for biomolecules, however, more than 99% of the molecular species in the laser desorbed plume from the crystal remain neutral and undetected. One reason for this is that the ions in the matrix cluster (Mn) in the plume recombine with nearby counterions to form neutral molecules before desolvation.
In this study, the contribution of Mn in the plume was investigated by post-laser ionization. It was also experimentally clarified that there are spatial biases in the internal energy and molecular species distribution of neutral DHB molecules in the plume, which desorb and diffuse from the DHB crystal due to laser-induced phase explosion.

Free Research Field

物理化学

Academic Significance and Societal Importance of the Research Achievements

MALDI法は、生体分子等のソフトイオン化手法として広く用いられているが、MALDIイオン生成機構については全てが解明されているわけではない。本研究で得られた知見は、MALDIイオン生成機構の特に初期過程の解明に寄与するものであるが、仮に今後MALDIイオン生成機構の全貌について解明できれば、MALDI法におけるイオン生成効率を向上させることができる可能性があり、試料検出感度の向上に繋がることが期待される。